1.Primary tumor (T) stage
The size of primary tumor cannot be measured; or cancer cells are found in sputum exfoliated cells or bronchial flushing fluid, but no primary tumor is found in imaging and bronchoscopy
T0
No evidence of primary tumor
Tis
Carcinoma in situ
T1
Primary tumor ≤3cm, surrounded by lung or dirty pleura, not involving lobar bronchus above proximal position
T1a Primary tumor ≤2cm
T1b Primary tumor >2cm but ≤3cm
T2
Tumor >3cm but ≤7cm, or any of the following: involvement of the main bronchus but ≥2cm from the bullae; involvement of the dirty pleura; partial atelectasis/obstructive pneumonia spreading to the hilum but not involving the whole lung
T2a Tumor >3cm but ≤5cm
T2b Tumor >5cm but ≤7cm
T3
Tumor >7cm or involvement of chest wall/diaphragm/phrenic nerve/pericardium/mediastinal pleura; tumor located in the main bronchus (<2cm from the bullae but not reaching the bullae); total pulmonary atelectasis/obstructive pneumonia; separated cancerous nodules in the same lung lobe as the primary tumor
T4
Invasion of mediastinum/heart/major blood vessels/rons/trachea/esophagus or vertebral body; cancer nodes with separation in different lung lobes on the same side of the primary tumor.
2.Lymph node metastasis (N) stage
Nx
Lymph node metastasis cannot be determined
N0
No regional lymph node metastasis.
N1
Ipsilateral bronchial and hilar lymph node metastasis.
N2
ipsilateral mediastinal and subserosal lymph node metastasis.
N3
Contralateral mediastinal, hilar, ipsilateral or contralateral oblique angle muscle, supraclavicular lymph node metastasis.
3.Distant metastasis (M) stage
Mx
The presence or absence of distant metastases cannot be evaluated.
M0
No distant metastasis.
M1a
Pleural dissemination (malignant pleural effusion, pericardial effusion or pleural nodules), presence of isolated cancer nodules in the lung lobe contralateral to the primary tumor.
M1b
With distant metastasis (pulmonary/extrapleural)
4.Specific staging.
Occult stage
TxN0M0
Stage 0
TisN0M0
IA stage
T1N0M0
IB period
T2aN0M0
Phase IIA
T2bN0M0, T1N1M0, T2aN1M0
Phase IIB
T2bN1M0, T3N0M0
Phase IIIA
T1~2N2M0, T3N1~2M0, T4N0~1M0
Phase IIIB
T4N2M0, TanyN3M0
Phase IV
TanyNanyM1
Note: 1. Any size of uncommon superficially disseminated tumor is defined as T1 as long as its infiltrative component is confined to the bronchial wall, even if it is adjacent to the main bronchus; 2. Most patients with lung cancer have pleural effusion (pericardial effusion) caused by tumor, but a few patients have multiple negative cytopathological examinations of pleural effusion (pericardial effusion), which is not a hemorrhagic fluid or an exudate. When the above factors are taken into consideration and it is determined that it is not tumor-related, the effusion will not be used as a basis for staging, and patients will be staged according to T1, T2, T3, and T4.